MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) wants to convert laser cutters into something more. By attaching a head to a commercial laser cutter and adding software, they combine the functions of a cutter, a conductive printer, and a pick and place system. The idea is to enable construction of entire devices such as robots and drones.
The concept, called LaserFactory, sounds like a Star Trek-style replicator, but it doesn’t create things like circuit elements and motors. It simply picks them up, places them, and connects them using silver conductive ink. You can get a good idea of how it works by watching the video below.
There are an awful lot of machines on the market these days that fall under the broad category of “cheap Chinese laser cutters”. You know the type — the K40s, the no-name benchtop CO2 cutters, the bigger floor-mount units. If you’ve recently purchased one of these machines from one of the usual vendors, or even if you’re just thinking about doing so, you’ll likely have some questions. In which case, this “Chinese Laser Cutters 101” online class might be right up your alley. We got wind of this though its organizer, Jonathan Schwartz of American Laser Cutter in Los Angeles, who says he’s been installing, repairing, and using laser cutters for a decade now. The free class will be on February 8 at 5:00 PM PST, and while it’s open to all, it does require registration.
We got an interesting tip the other day that had to do with Benford’s Law. We’d never heard of this one, so we assumed was a “joke law” like Murphy’s Law or Betteridge’s Rule of Headlines. But it turns out that Benford’s Law describes the distribution of leading digits in large sets of numbers. Specifically, it says that the leading digit in any given number is more likely to be one of the smaller numbers. Measurements show that rather than each of the nine base 10 digits showing up about 11% of the time, a 1 will appear in the leading digit 30% of the time, while a 9 will appear about 5% of the time. It’s an interesting phenomenon, and the tip we got pointed to an article that attempted to apply Benford’s Law to image files. This technique was used in a TV show to prove an image had been tampered with, but as it turns out, Hollywood doesn’t always get technical material right. Shocking, we know, but the technique was still interesting and the code developed to Benford-ize image files might be useful in other ways.
Everyone knew it was coming, and for a long time in advance, but it still seems that the once-and-for-all, we’re not kidding this time, it’s for realsies shutdown of Adobe Flash has had some real world consequences. To wit, a railroad system in the northern Chinese city of Dalian ground to a halt earlier this month thanks to Flash going away. No, they weren’t using Flash to control the railroad, but rather it was buried deep inside software used to schedule and route trains. It threw the system into chaos for a while, but never fear — they got back up and running by installing a pirated version of Flash. Here’s hoping that they’re working on a more permanent solution to the problem.
First it was toilet paper and hand sanitizer, now it’s…STM32 chips? Maybe, if the chatter on Twitter and other channels is to be believed. Seems like people are having a hard time sourcing the microcontroller lately. It’s all anecdotal so far, of course, but the prevailing theory is that COVID-19 and worker strikes have lead to a pinch in production. Plus, you know, the whole 2020 thing. We’re wondering if our readers have noticed anything on this — if so, let us know in the comments below.
And finally, just because it’s cool, here’s a video of what rockets would look like if they were transparent. Well, obviously, they’d look like twisted heaps of burning wreckage on the ground is they were really made with clear plastic panels and fuel tanks, but you get the idea. The video launches a virtual fleet — a Saturn V, a Space Shuttle, a Falcon Heavy, and the hypothetical SLS rocket — and flies them in tight formation while we get to watch their consumables be consumed. If the burn rates are accurate, it’s surprising how little fuel and oxidizer the Shuttle used compared to the Saturn. We were also surprised how long the SLS holds onto its escape tower, and were pleased by the Falcon Heavy payload reveal.
[Brain] wanted to mark some scissors with his Ortur laser engraver. The problem? The laser won’t cut into the hard metal of the scissors. His solution? Smear the scissors with mustard. No kidding. We’ve heard of this before, and apparently, you can use vinegar, as well, but since the mustard is a paste it is easier to apply. You can see the result in the video, below.
In case you think you don’t need to watch because we’ve already told you the trick, you should know that [Brian] also goes into a lot of detail about preparing single line fonts to get a good result, among a few other tips like improvements to his air assist setup. On a laser cutter, the air assist blows away charred material leaving a clear field of view between the laser and the remaining uncut material. Using a proper air assist can really expand the capabilities of these inexpensive laser cutters — something we recently saw upgraded with a 3D-printed air assist nozzle.
You can buy a commercial marking solution called CerMark Black, but you probably already have mustard. If you are super cheap, you can probably pick up a packet next time you buy a burger somewhere. After all, you don’t need much. Although the video talks about the Ortur, this technique would work with any engraver. We’ve also heard you can do something similar with plaster and alcohol.
A laser cutter is an incredibly useful tool and they are often found in maker spaces all over. They’re quite good at creating large two-dimensional objects and by cutting multiple flat shapes that connect together you can assemble a three-dimensional object. This is easier when creating something like a box with regular 90-degree angles but quickly becomes quite tricky when you are trying to construct any sort of irregular surface. [Tuomas Lukka] set out to create a dollhouse for his daughter using the laser cutter at his local hackerspace and the idea of creating all the joints manually was discouraging.
The solution that he landed on was writing a python script called Plycutter that can take in an STL file and output a series of DXF files needed by the cutter. It does the hard work of deciding how to cut out all those oddball joints.
At its core, the system is just a 3D slicer like you’d find for a 3D printer, but not all the slices are horizontal. Things get tricky if more than two pieces meet. [Tuomas] ran into a few issues along the way with floating-point round-off and after a few rewrites, he had a fantastic system that reliably produced great results. The dollhouse was constructed much to his daughter’s delight.
At this point if you’re even remotely interested in home laser cutters, you know about the K40. These imported machines are very impressive considering they only cost around $400 USD, but naturally, quite a few corners had to be cut to get the price down. If you’re looking for something with a bit more punch and much higher build quality, a new breed of 60 watt lasers have started popping up on the usual import sites for around $2,000 USD.
While these more expensive machines are certainly much higher quality than the K40, [Jeremy Cook] found there was still plenty of room for improvement. For example, the machine didn’t have any switch cut off the laser when somebody opens the lid. While we don’t doubt some readers will consider this more of a feature than a bug, it’s hard to believe that a tool that costs this much wouldn’t at least offer such a thing as an option.
Drilling a hole for the ammeter.
[Jeremy] also decided to add his own ammeter so he could see how much power the laser is drawing. While not strictly required for day to day operation, it turns out that the controller in many of these machines has a tendency to push the laser tubes beyond their design limits on the higher power settings. With the spec sheet for your tube and a permanent in-line ammeter, you can verify you aren’t unwittingly shortening the life of your new cutter.
Even if you ignore the modifications [Jeremy] makes in his video, it’s still a very illuminating look at what it takes to get one of these lasers ready for operation. Not only do you have to get the thing out of its shipping crate safely, but you need to come up with some way to deal with the fumes produced and get the water cooling system hooked up. It’s a decent amount of work, but the end results certainly look impressive.
While the K40 is still probably the better bet for new players, it’s good to see that there are some viable upgrades for anyone who’s outgrown their entry level machine but isn’t in a position to spend the money on an Epilog.
The air assist helped clear the cut parts and reduced charring in the wood. The air system clears residue and fumes that can reduce the effectiveness of the laser. It can also reduce the risk of the workpiece catching on fire.
As the coronavirus pandemic circles the world, a fact of daily life for millions of people has become the wearing of a face mask. Some people sport colorful fabric masks, but for many, this means the ubiquitous Chinese disposable mask. They have become the litter of our time, which as [blorgggg] notes is something that shouldn’t have to be the case. Their plastic can be recycled and made into other useful things, for example, ear savers similar to the ones many of us were 3D printing earlier in the year.
As you might imagine diving into a pile of used masks can be a little unhygienic, so the first step is to disinfect with alcohol. Then the various layers can be separated and the outer polypropylene ones collected and stacked between baking parchment to be melted on a skillet. The result is a polypropylene sheet that can be laser cut if it is thick enough, and from this are cut the ear savers. It’s not quite as neat a cut as the acrylic sheet we may be used to, but it’s adequate for the task.
